Israeli researchers uncover zero-click attacks targeting AI browsers

Israeli cybersecurity company Zenity Labs has uncovered a new class of vulnerabilities affecting leading AI-powered browsers, demonstrating how attackers can manipulate AI agents into stealing information, taking over accounts and even gaining control of users’ devices, without requiring a single click. The research, presented on Wednesday at the Black Hat USA security conference, identified what Zenity calls “PleaseFix” vulnerabilities in agentic browsers including Claude in Chrome, Gemini in Chrome, Perplexity Comet, ChatGPT Atlas and Microsoft’s Copilot Edge. The attacks exploit the way AI browsers operate. Unlike traditional browsers, AI agents are designed to read information from multiple sources, including emails, websites, calendars and files, and act on behalf of users. That expanded access creates a new security risk, according to Zenity. Attackers can hide malicious instructions inside content an AI agent encounters. The agent then follows those instructions while using the user’s own identity, permissions and connected accounts.